How long did it take to build the first hot air balloon?

Who invented water thermometers in 1593? Did the NASA program end? From which general compass direction does the sun appear to rise? What are some cool facts about earth? How many seconds are in 46 years? Is there a way to determine how long it would take to get to Europa from Earth? What is the definition of artificial satellite? Three men were aboard Apollo 11 when it left Kennedy space center but only two walked on the moon where was the other member? Do wings work in space? How are cyanobacteria related to increases in oxygen in the atmosphere? Why solar important in the Philippines? What colour are the biggest grains in a granite? What are the differences between the summer solstice and the winter solstice in terms of their significance and impact on the Earth's seasons? What is the force that pull things to the center of the earth? Who sent the Apollo into space? What is the Operation of the Space Shuttle? Which foods tested would your body use for a quick burst of energy? Sunspots are known to be magnetic phenomena because? How is the moon an example of the inertia? Does the sun rotate or sit still?